An electric vehicle mounting a battery and an electric motor as a driving source has advantages of no exhaust gas emission and less noise generation. However, in the event of vehicle stall due to battery power exhaustion, unlike a conventional gasoline engine vehicle, it is not possible to revive the vehicle by carrying in an amount of gasoline, but the vehicle needs to be towed to a nearby charger station by a tow track. Also, if a large battery is mounted for enabling driving for an extended period, there will arise a problem of increase of vehicle weight and vehicle occupying space. In particular, increase of vehicle body weight invites such inconveniences as need for increase of vehicle body strength, deterioration of fuel consumption efficiency.
Then, in an attempt to restrict occurrence of such problems as above, e.g. Japanese Unexamined Patent Application Publication No. 2010-200393 proposes an auxiliary battery charger device for an electric vehicle comprising a towed vehicle mounting an auxiliary battery and a charger and configured to be towed by the electric vehicle. This auxiliary battery device includes a connection arm for towing by the electric vehicle and a connection cable for connecting a battery of the electric vehicle to the charger. When the charged power of the battery of the electric vehicle has been used up, this battery and the auxiliary battery will be connected via the connection cable, so that the battery of the electric vehicle can be charged.
In a fork lift disclosed in Japanese Unexamined Patent Application Publication No. 2014-082339 (FIGS. 7-17), a secondary side contactless power transfer pad (a secondary coil) configured to receive electric power via electromagnetic coupling with a primary side contactless power transfer pad (a primary coil) installed on a ground surface is provided between front wheels and rear wheels and mounted to a lower face of one lateral face of the fork lift. In the case of such fork lift, there is relatively ample space available between the front wheels and the rear wheels under the vehicle body in case a fork lift mechanism as an utility implement mounted on the traveling vehicle body is disposed forwardly of the front wheels. Therefore, the secondary side coil can be disposed between the front wheels and the rear wheels. The primary side coil is provided on the ground surface or a support platform installed on the ground surface.